1. Field of the Invention
The invention relates to internal combustion engines and, in particular, to rotary internal combustion engines driven by the sequential combustion of combustible fuel in a plurality of internal combustion chambers.
2. Description of the Related Art
A considerable amount of research in rotary cycles was done in the 1920's and 1930's. Many types of rotary cycles were considered. The development lead to the most famous of rotary engines, namely the Wankel engine. Many mechanical problems were solved during that time. However, even though the rotary cycle is superior to the Otto cycle in all theoretical thermodynamic calculations, only one large series automobile, i.e., the Mazda RX-7, utilizes the Wankel cycle.
The instantly proposed system deviates considerably from the Wankel system, most notably in the differences regarding compression. A certain amount of teaching may nevertheless be transferred, for instance seal and spark plug placement information.
Most prior art rotary engines utilize the rotor to compress the fuel/air mixture directly in the combustion chamber. The rotor is thereby radially asymmetric, it is mounted eccentrically relative to the rotor chamber, or the chamber is not circular. Examples of such engines are found in U.S. Pat. Nos. 4,075,981 to Durst, 3,301,233 to Dotto et al., and 3,782,110 to Kobayashi, respectively. An alternative design was recently proposed in U.S. Pat. No. 5,429,084 to Cherry et al. where the rotor and the chamber are radially symmetrical and the combustion chambers are instead formed laterally on either sides of the rotor and several vanes move axially to close off the combustion chambers. The compression "stroke" is effected by the narrowing of the combustion chamber during the angular displacement of rotor relative to the rotor housing (the stator) and the reduction in chamber volume effected by the respective vane.
As noted above, the rotary cycle is superior to the Otto cycle on paper. In reality, however, Otto cycle engines are quite principally better in terms of thermodynamic efficiency. Whether or not this has anything to do with the fact that much more research has been invested in the Otto cycle as compared to the rotary cycle cannot be easily answered. It should be possible, however, to improve a rotary engine further so that its actual efficiency approaches the theoretical limits more closely.